An optical membrane redox chemical sensor for the determination of ascorbic acid

Abstract

The redox indicator, ferroin, tris(1,10- phenanthroline)iron(II) was incorporated into the perfluorosulfonated cation-exchange membrane Nafion and, together with optical fibers, a photodiode, and a light-emitting diode, was used for the construction of a redox optical sensor (optode). The optode was incorporated in the flow-through cell of a computer-controlled sequential injection (SI) system and used for the determination of ascorbic acid (vitamin C). A linear relationship between the logarithm of the ascorbic acid concentration and the membrane absorbance was obtained for the concentration range from 2.50×10 to 1.00×10 mol L and a sample frequency of 17 h . The concentration of ascorbi..